Visualization of Variability Analysis of Control Software from Industrial Automation Systems

Industrial automated production systems are mechatronic and long living systems that undergo changing requirements throughout their life cycle. While the proportion of functionality implemented by software is growing, adjustments are usually implemented using a clone-and-own principle, which results in unmanaged software variants and versions. Furthermore, the need for adapting the control software also results from changes in other disciplines such as mechanical or electrical/electronics. The various drawbacks on software maintainability, that are provoked through clone-and-own, call for a shift to modular development. As a first step to realize this migration, software projects need to be analyzed in terms of variability. Secondly, visualization patterns reflecting variability are needed to present the analysis results to domain experts. However, choosing an appropriate visualization is challenging as different domain experts pursue different aims, which should be supported by the visualization and might even require different levels of detail. In this paper, visualization patterns for three different use scenarios are proposed and evaluated using an apprentice group and industrial expert feedback.